1. Field of the Invention
This invention relates to solar heating systems and, more particularly, to control systems for optimizing the operation of such systems.
2. Prior Art
In solar water heating systems having open or closed-loop water pump control, it is quite conventional to utilize a photo responsive transistor or diode to sense the existence of insolation, or lack thereof, in order to control the pump moving water, or other heat transferring fluid, through the solar panels upon which the sun's rays are falling. In such a control system, every time a cloud passes across the path of light from the sun to the solar panel, the pump is shut off and is re-started when the cloud has passed. Every time the pump is turned on and off it, of course, produces current surges in the power line with the result that the operation of other appliances connected to the same power line is disturbed. Further the current-surges through the pump motor reduce its life. Electromagnetic noise from such on-off operation can interfere with television and radio reception and with other communications operations.
Therefore, it is an object of this invention to eliminate the various problems which have been set forth hereinbefore.
It is a further object of this invention to provide, in a solar heating system, a pump control circuit which produces minimum on-off switching of the pump motor to assure reduced interference from and longer life for the solar heating system.